libgccjit: Add support for bitcasts [PR104071]

libgccjit: Add support for bitcasts [PR104071]

gcc/jit/
	PR jit/104071
	* docs/_build/texinfo/libgccjit.texi: Regenerate.
	* docs/topics/compatibility.rst (LIBGCCJIT_ABI_21): New ABI tag.
	* docs/topics/expressions.rst: Add documentation for the
	function gcc_jit_context_new_bitcast.
	* jit-playback.cc: New function (new_bitcast).
	* jit-playback.h: New function (new_bitcast).
	* jit-recording.cc: New functions (new_bitcast,
	bitcast::replay_into, bitcast::visit_children,
	bitcast::make_debug_string, bitcast::write_reproducer).
	* jit-recording.h: New class (bitcast) and new function
	(new_bitcast, bitcast::replay_into, bitcast::visit_children,
	bitcast::make_debug_string, bitcast::write_reproducer,
	bitcast::get_precedence).
	* libgccjit.cc: New function (gcc_jit_context_new_bitcast)
	* libgccjit.h: New function (gcc_jit_context_new_bitcast)
	* libgccjit.map (LIBGCCJIT_ABI_21): New ABI tag.

gcc/testsuite/
	PR jit/104071
	* jit.dg/all-non-failing-tests.h: Add new test-bitcast.
	* jit.dg/test-bitcast.c: New test.
	* jit.dg/test-error-bad-bitcast.c: New test.
	* jit.dg/test-error-bad-bitcast2.c: New test.

gcc/
	PR jit/104071
	* toplev.cc: Call the new function tree_cc_finalize in
	toplev::finalize.
	* tree.cc: New functions (clear_nonstandard_integer_type_cache
	and tree_cc_finalize) to clear the cache of non-standard integer
	types to avoid having issues with some optimizations of
	bitcast where the SSA_NAME will have a size of a cached
	integer type that should have been invalidated, causing a
	comparison of integer constant to fail.
	* tree.h: New function (tree_cc_finalize).